Rainbows 3.4.0 - minor updates and fixes

SIGQUIT (graceful shutdown) now drops idle keepalive clients for
the concurrency models where maintaining an idle client is
relatively inexpensive: Coolio, CoolioThreadPool,
CoolioThreadSpawn, Epoll, EventMachine, XEpoll,
XEpollThreadPool, XEpollThreadSpawn.

Kgio.autopush now works properly for all multi-threaded
concurrency models (if you're using :tcp_nopush).